Enter the sum of all squared percentages in the distribution and the number of categories into the calculator to determine the IQV.

## IQV Formula

The following formula is used to calculate an index of qualitative variation (IQV).

IQV =[ K ( 1002 – SUM (Pct2 )) ] / 1002 (K-1)

• Where IQV is the index of qualitative variation
• K is the number of categories
• Pct^2 is the sum of all squared percentages in the distriubution

## IQV Definition

IQV, which is short for the index of qualitative variation, is a measure of the variability for nominal variables such as race and ethnicity.

IQV values rand from 0 – 1. IQV is 0 when all cases in the distribution are in one category and IQV is 1 when all cases are distributed evenly in each category.

## Example Problem

How to calculate IQV?

1. First, determine the total number of categories.

For this example, there are 20 total categories.

2. Next, determine the sum of all squared percentages in the distribution.

The sum of the percentages for this example is found to be 7525.

3. Finally, calculate the index of qualitative variation.

Using the formula above, the IQV is calculated to be:
IQV =[ K ( 1002 – SUM (Pct2 )) ] / 1002 (K-1)
IQV =[ 20 *( 100^2 – 7525) ] / (100^2 * (20-1) )
IQV = .260